Don't call it a comeback. No, seriously: don't. A game called Flappy Bird: New Season may have flown to the top of Apple's App Store charts, but it doesn't appear to be the work of the original Flappy Bird developer Dong Nguyen.

Something strange is afoot with Flappy Bird: New Season, which is currently the most popular free iPhone download on Apple's UK store, and the fourth most popular free iPad download behind Microsoft's Word, PowerPoint and Excel.

Is it the real return of Flappy Bird? Almost certainly not. The game was not released through Nguyen's existing App Store developer account, for example, where he still has his Shuriken Block and Super Ball Juggling games available. Meanwhile, on Twitter there's an excitable quote that purports to be from Nguyen:

Again, this isn't Dong Nguyen's official Twitter account – his handle is @dongatory without an _ on the end, and his last tweet was on 23 March.

The @dongatory_ account claims to be a "backup" for Nguyen's official account, but past tweets like "RT if you want a free itunes gift card :)" and "Let's trend a hashtag to be easier! Hashtag #dongatory_ as much as you can lets trend it!! #dongatory_ :-)" don't seem a good fit for the famously-shy Flappy Bird developer.

In short, Flappy Bird: New Season almost certainly isn't the return of the original Flappy Bird to iOS and Android. So why write a story about it? Because its success raises big questions about how the game managed to rise to the top of the App Store chart so quickly, at a time when Flappy Bird clone-fever has been dying down.

This isn't just a quirk in the UK App Store. Flappy Bird: New Seasons is the third top free iPhone app in the US too, where it also has a four-star rating, this time from 659 reviews, most of which are glowing.

The sudden success of the original Flappy Bird provoked speculation that Nguyen had in some way gamed the charts – he denied this – but the rapid rise of Flappy Bird: New Season may be a spur for more debate about the value of those charts to Apple, developers and players alike.

Update: As independent developer Matthew Wiggins points out on Twitter, search placement is likely to be a big factor in the game's rise: